At the beginning of the BBC1 series Jessie, 24, was odds-on favourite to coach the winner, but now she finds herself with the least popular acts.

A Ladbokes spokeswoman said: “Sir Tom Jones at 5/2 and his act Ruth Brown at 11/4 are the big market movers this week. They are beginning to steal the limelight even from Jaz Ellington at 3/1.”

This week’s show sees Jessie and coach Danny O’Donoghue both having to lose some of their acts.

Meanwhile, on ITV1, the Britain’s Got Talent judges must also break hearts as Simon Cowell reveals which of the 44 acts will get through to the live semi-finals.

On tonight’s show, in Cardiff, Channel charity swimmer and judge David Walliams is “blown away” by a synchronised swimming group.

For me the star of the show was the saucepan, it’s obviously a good one, non-stick

David Walliams

The show gets off to a chilly start for audience and judges alike when everyone heads outside to see them performing in a specially-built tank which Cowell dubs “the human aquarium”. The all-girl group, called Aquabatique, is made up of Emily, Zoe, Jazmine and Elizabeth, who are aged 21 to 28. Walliams tells them: “You need such strength to do that, but you also need real grace and beauty and you girls have got both. I was blown away.”

But it is more like Britain’s Got Tardis when Dalek impersonator Martyn Crofts tries to impress the judging panel. The building society worker from Skipton in North Yorkshire does his audition armed only with a saucepan in what he says is his “absolutely unique” act.

Walliams jokes with him: “For me the star of the show was the saucepan, it’s obviously a good one, non-stick.”

Other acts include a contortionist, two drag queens and a Michael Jackson impersonator. But 25-year-old Londoner Rachel Knowland could be the one to watch with a beautiful rendition of VV Brown’s Shark In The Water.